When the Last Petal Falls
by RanMouri82
Summary: "Each time I grow a new flower, his heart breaks." Flowerfell AU
**Title:** When the Last Petal Falls

 **Author:** RanMouri82

 **Rating:** PG-13

 **Disclaimer:** Toby Fox owns Undertale. I own my fangirling.

 **Notes:** "Each time I grow a new flower, his heart breaks." Flowerfell AU

 _When the Last Petal Falls_

Waterfall's damp atmosphere made Sans' fur-lined coat feel bulky and sticky where it draped on Frisk. It hung loose on them, made as it was for a short monster rather than an average human. But the humidity carried the deep cavern's chill, and Frisk did not want to risk falling sick again. Besides, the warm fabric and its scent made them feel wrapped and safe, like the child the enormous monsters often mistook them as being.

"Hey, Frisk?" Flowey piped up from over their head, one large blossom hovering above their blinding crown of tiny buttercups. He wound his vines around Frisk's thin shoulders as gently as possible to avoid snagging the flowers that poked out in clusters from their collar. No matter how much the human smiled and protested they were fine, Flowey knew that tugging any one of those cursed flowers made them recoil in pain. He glanced a stone's throw ahead at the back of Sans' skull, judging that the burly skeleton was just out of earshot.

Frisk nodded for Flowey to continue.

"Why did you want me to guide you this time?" Flowey asked. "I mean, I wouldn't trust that guy to carry me, either, but—"

"It's not that," Frisk said, their voice hushed. "I trust him now. He's a good person."

"That's a stretch," Flowey hissed, resting his blossom on the top of Frisk's head. "It's okay to walk, but to get past Undyne's spears we need to run, remember?"

"I know," Frisk said, pressing their hand to their chest. Their human soul lay within a mesh of sprouted flowers, many of them caused by the ferocious Undyne. "All three of us remember whenever I reset. Each time I grow a new flower, he..."

"Sans?" Flowey blinked.

Frisk smiled sadly, just visible to Flowey beneath their tangle of hair and flowers. "His heart breaks. I don't want to make it worse."

Flowey scanned the warped boardwalk and gazed down at his friend's face. Sans' footsteps echoed and clanked ahead of them, but Frisk's were feather light. Maybe the lack of snow had softened their steps. Maybe they were fading away. "He's getting really attached to you, you know."

"I know," Frisk said, their voice hoarse. "That's what I'm trying to stop."

The human and flower walked in tandem for awhile. Flowey tugged Frisk's arms in the direction they needed to walk while Sans kept his distance, jerking into a defensive stance each time a reed bobbed or a flower echoed.

"I think I understand," Flowey said, finally, dipping his blossom into the shadow beside Frisk's head. Bending toward the human's ear, he whispered a question.

Frisk gasped, clenched their throat, and halted.

"Huh?" Sans stopped walking and turned around with a grunt. "Tired already, sugar?"

"Maybe," Frisk said, suddenly feeling dizzy—or giddy? "I need a break."

"Sure. There's a rock to sit on over there," Sans said, gesturing toward a cavern wall before remembering Frisk could not see it. Taking them by the hand, he led Frisk to an outcropping and lowered them onto it.

For a full minute, the trio waited there in awkward silence. Sans paced with his hands in his pockets, Flowey examined some of his damaged stems, and Frisk fidgeted with a drawstring on Sans' coat.

"Since we're waiting, anyway," Flowey said, looking back along the path they just traveled, "I'll go make sure we're not being followed."

"Hey—!" Frisk cried, reaching out their hand toward the voice, but it was too late. Hearing a wet pop in the ground by their chilled feet, they knew Flowey was already gone.

Sighing, Frisk played with the coat's sleeves. Their heart started to pound, however, when they heard and felt Sans sit beside them.

Leaning his elbows against his knees, Sans muttered, "You've been quiet. Well, quieter than usual."

They chewed on their lower lip and nodded.

"Doesn't take a genius to see you're avoiding me, too." His deep voice growled out of frustration.

"I-I'm sorry," Frisk said. They danced their fingertips along the flower line of their wrist, knowing both their hands were slowly growing numb. "It's not you."

"Heh. 'It's not you, it's me'? That kind of bullshit doesn't suit you, honey." Sans turned to face the human, and his kneecap bumped theirs. "What's really going on?"

When Frisk continued to fidget, Sans grabbed his forehead. "Dammit, sweetheart, I'm not cut out for soul-to-souls, but unless you want Undyne to skewer you like a fish—"

"I don't want you to risk yourself for me," Frisk said, sitting up straight and clenching their fists. "You've changed, you know? I can feel it. You chose to become a good person. You're warm and you care."

Sans' face flashed red.

"I am still determined to get out," Frisk continued, pointing up to the rocky ceiling, "but I don't know if that will happen."

"I'm getting you outta here," Sans grumbled, eyeing Frisk. "Half those flowers came from me. Even I don't remember how many times I killed you."

"You don't owe me anything," Frisk said. A whimper creeped into their throat and they fought to suppress it. "No matter what happens, I don't want to hurt anyone. I don't want to hurt you. But every time I die, I hurt you over and over."

"...What makes you think that?"

"I feel it. Here." Frisk pointed to their chest. "You have changed, Sans. I don't want to ruin that for you."

They felt Sans edge closer.

Shivering despite the muggy air, Frisk said, "Please, forget about me."

"Oh man," Sans said, clenching his jaw and trembling. "You're a real piece of work, honeybunch." He grabbed Frisk's hand. His hand was warm, somehow; theirs felt clammy. "You think I can ever forget you?"

Frisk hung their head.

"Hey." Sans' face glowed, but he shook his head and kept talking. "Do you like being with me?"

Frisk hesitated, blushing, but then gave a vigorous nod. "Do you?"

"Yeah," Sans said, curling his fingers around theirs. "So. The problem is?"

"I can't promise you I'll stay." Sniffling, Frisk tried to pull their hand free but could not will their arm to move. "And I don't want to let go."

"Believe me," Sans said, dropping his voice low and releasing Frisk's hand to grip their shoulders, "that's not a problem."

Frisk caught their breath as Sans drew them into the circle of his arms. Knowing what was happening, their heart leaped to their throat. His face brushed their cheek and then, with care, found their lips.

A tingling, warming sensation grew there, filling their mouth and drawing them into its sweetness. Frisk felt their heart race faster. Everything in them screamed 'Don't! Stop! You'll hurt him! This isn't kind!', but they could not push away. They wanted this far too much.

Instead, they reached around the back of Sans' sweater and sank into his chest, feeling him do the same and letting his scent envelop them.

A sigh escaped their lips. It felt cruel and wonderful. They never wanted it to end.

Breathlessly, the two finally broke apart. Swallowing hard, Frisk said, "Sans?"

"Yeah?"

"You kissed me."

"...Yeah."

Smiling, Frisk felt their eyes fill with tears. Figures the flowers blinded them without plugging their tear ducts. Frisk burrowed their face into Sans' sweater as much as their thick cluster of flowers would allow. "I'm glad."

"Me too," Sans said.

A silent moment hung there as Frisk felt his warm breath tickle their hair. A cough sounded in the distance.

"Um, the path from Snowdin's clear," Flowey said, his voice quavering. "Papyrus isn't following us."

"Oh," Sans said, jumping backward. He touched the back of his skull and looked away. "Good. Now we gotta watch out for Undyne. I'll go ahead to check, so stay here, will ya?"

Flowey bobbed his stem in agreement, and Sans nodded his thanks.

Frisk heard the hard thuds of Sans' footsteps fall softer and softer until they disappeared. "Flowey?"

"Yeah?"

Frisk paused. "You saw."

"...Yeah."

Around them, the running streams of Waterfall bubbled. Frisk pressed both hands against the flat stone where they sat.

"You know," said Flowey, his laugh soft and sad, "back when I was alive, monsters were rough, but not like this." Flowey blinked up at Frisk as pale, blue light from the surrounding marsh cast a lace shadow through their many buttercups. "It may be hard to believe, but Mom and Dad were really mushy. As a kid, it grossed me out to always see them nuzzling noses. Seeing you two was weird, but it reminded me of that. Maybe because whenever they were lovey-dovey, my mom smiled biggest. She looked like you do, Frisk."

A hot blush framed the buttercups as it bloomed on their face.

"In a way, it made this place nicer," Flowey said, smiling, knowing Frisk could not see it but could hear it in his voice.

"You were right. I'm scared," Frisk said, a single tear sliding down their reddened cheek, "because I love him."

Flowey twisted his vines, uncomfortable.

Bending low towards Flowey, Frisk whispered, "If I don't make it, what will he—?" they broke off, brushing their fingertips along the ring of soft petals that bound their head, "will he...?"

Reaching a leaf to wipe the tear from Frisk's face, Flowey said, leaning in to their ear out of the range of the echo flowers, "I'll look after him. I promise."

Frisk curled their fingers to catch the tears that kept flowing over their smiling lips. "Thank you."

The two of them said nothing after that but sat and listened to the rush of water. Frisk laid their hand on their chest once more, feeling the same warmth as earlier swell within their soul. They yielded to it.

Soon, Sans' heavy footfalls returned. When Sans eventually stopped beside Frisk, he coughed. "I don't see Undyne around, so now might be a good time to move forward."

Nodding, Frisk reached up and took the bony hand they knew would be waiting. "Flowey thinks we'll move faster if you carry me."

"Heh, that's what I've been saying all day, sweetheart. Figures you'd listen to the plant," Sans said, laughing as the dim marsh's light caught his gold tooth.

"Gee, thanks," huffed Flowey, folding his leaves like a pair of indignant arms. Sans ignored him and crouched to let Frisk climb onto his back. For a moment, as Sans straightened with Frisk holding him in a firm piggyback, it struck Flowey that he spied Sans' true smile. As the trio resumed their journey, Flowey quirked a smile of his own and murmured, "You're welcome."


End file.
